Linked Tooth Digging Chain

ABSTRACT

A digging chain for a trencher with a repeated pattern of single-piece toothed links, The single-piece teeth are pivotally connected on each side to an adjacent link. The single-piece teeth comprise a repeating pattern with the first and second teeth having different shapes on the same side of the digging chain, and the third and fourth teeth are on an opposite side of the digging chain.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of provisional patent application Serial No. 62/068,087 filed on Oct. 24, 2014, the entire contents of which are incorporated herein by reference.

FIELD

The present invention relates generally to digging chains for trenchers.

SUMMARY

The invention is directed to an endless digging chain. The endless digging chain is formed from a plurality of pivotally interconnected links arranged in laterally spaced first and second flights. The plurality of links include a first tooth, second tooth, and third tooth. The first tooth is positioned in the first flight, has a first shape, and formed as a single-piece tooth. The second tooth is positioned in the first flight and formed as a single-piece tooth having a second shape. The second shape is different than the first shape. The third tooth is positioned in the second flight and formed as a single piece tooth.

In another embodiment, the invention is directed to an endless digging chain. The digging chain comprises a plurality of untoothed links and a plurality of teeth, The plurality of untoothed links defines a width. The plurality of teeth are each pivotally connected on each end to one of the plurality of untoothed links, The plurality of teeth define a repeating pattern of four distinct tooth profiles relative to the width.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a trencher using the endless digging chain of the present invention.

FIG. 2 is a perspective view of a digging chain.

FIG. 3 is a side view of the digging chain of FIG. 2.

FIG. 4 is a top view of the digging chain of FIG. 2.

FIG. 5 is a side view of an alternative digging chain.

DETAILED DESCRIPTION

The present invention is directed to an improved digging chain for use with a trencher boom. Traditional digging chains consist of a system of links with bolted-on teeth attached to the links. The links each pivot relative to each adjacent link and proceed in an endless fashion about a trencher boom. In this way, teeth are rotated about a trencher boom to uncover a trench in an “endless” manner.

With reference now to FIG. 1, shown therein is a trencher 10 comprising a digging chain 12 disposed about a trenching boom 14. The trencher 10 shown herein is a “walk behind” model, meaning that a user walks behind a control panel 16 as opposed to riding on a platform or tractor-mounted operator station, though the digging chain 12 of the particular invention may be utilized with many different types of trencher. The trencher 10 comprises a rotatable auger 18. The digging chain 12 and auger 18 are driven by a motor 20. As dirt and debris (referred to herein as “spoils”) are removed from the ground by operation of the digging chain 12 and deposited next to the trenching boom 14, the auger 18 rotates to move the spoils away from the newly uncovered trench. While one auger 18 is shown on the trencher 10 in FIG. 1, a second auger may also be utilized on an opposite side of the trenching boom 14.

The trencher 10 further comprises two drive wheels 22 and one trail wheel 24, The drive wheels 22 provide motive force to the trencher 10. During trenching operations, the drive wheels 22 translate the trencher 10 across the ground in a direction D. The trail wheel 24 provides support for the weight of the trencher boom 14 and auger 18. Alternatively, the trencher 10 may utilize tracks or a combination of wheels and tracks.

The digging chain 12 comprises a plurality of teeth 50 connected by a plurality of links 52. The teeth 50 are all single-piece items, and are connected to adjacent links 52 but not bolted on to any additional structure. Each of the teeth 50 comprises a shape, which may be similar or different from one or more of the other teeth on the digging chain 12. The digging chain is rotated about a head sprocket (not shown) driven by the motor 20. A tail sprocket 54 is supported at an end of the trencher boom 14 to engage the digging chain 12 as it rotates about the trencher boom. As shown in FIG. 1, to perform trenching operations, the digging chain 12 rotates counter-clockwise about the trencher boom 14 as the trencher 10 moves in the direction D.

With reference now to FIG. 2, each tooth 50 is connected on each side to one of the plurality of links 52. Each link 52 consists of a pair of support bars 60 each pivotally connected to an adjacent link at a pivotal connection 62. As shown, some of the support bars 60 comprise the teeth 50. Rather than bolting to links, the teeth 50 are themselves structural elements within the digging chain 10 that act as support bars 60 within certain links 52. The pivotal connection 62 may comprise a pin, bolt, or other suitable means for pivotally connecting adjacent links 52. The pivotal connection 62 further comprises a roller 64 disposed between the support bars 60. The roller 64 is rotationally independent of the links 52 and teeth 50. In addition to connecting the support bars 60, the rollers 64 of pivotal connection 62 provide an engagement point for teeth of the head sprocket (not shown) and tail sprocket 54 (FIG. 1).

The digging chain 12 comprises external untoothed links 52A and internal untoothed links 52B. The support bars 60 of the external links 52A are disposed outside of internal links 52B when connected at the pivotal connection 62. As shown, each of the teeth 50 forms a support bar 60 of every second external link 52A, thus one tooth 50 is disposed every fourth link 52. One of skill in the art will appreciate that some applications may make it favorable for teeth to be placed closer together or further apart, and that there is no technical limitation in placing some or ail of the plurality of teeth 50 as a support bar 60 of an internal link 52B.

The plurality of teeth 50 comprises a first tooth 50A, a second tooth 50B, a third tooth 50C, and a fourth tooth 50D. The first tooth 50A and second tooth 50B are located on a first side of the digging chain 12 and form a first flight 68 of teeth 50 and links 52. The third tooth 50C and fourth tooth 50D are located on a second side of the digging chain 12 and form a second flight 69 of teeth 50 and links 52. Each tooth 50A, 50B, 50C, 50D comprises a different tooth profile, that is, the shape and position of the tooth relative to the digging chain 12. Having a first, second, third and fourth tooth profile allows the digging chain 12 to interact with a wide trench and avoid rutting, As shown, the second tooth 50B and third tooth 50C comprise substantially similar shapes but different profiles relative to the digging chain, as the second tooth 50B is in the first flight 68 while the third tooth 50C is in the second flight 69 of the digging chain. Similarly, the first tooth 50A and fourth tooth 50D comprise substantially similar shapes but different profiles. One of skill in the art will appreciate that all the teeth 50A-D could comprise different shapes. The shape of the second tooth 50B and third tooth 50C may be mirror-images of the first tooth 50A. Alternatively, each of the first tooth 50A, second tooth 50B, third tooth 50C and fourth tooth 50D may comprise unrelated shapes. Additional teeth (not shown), with additional shapes may also be utilized.

As shown in FIG. 2, the teeth 50A-D form a repeating pattern of tooth profiles with three untoothed links 52 between each tooth. The number of untoothed links 52 between each tooth 50 may be varied, or the number of tooth profiles may be modified without departing from the spirit of the invention.

a distal portion of each tooth. The hardened tip 70 provides durability on the portion of the tooth 50A-D which engages unbroken soil and thus receives the most wear. Each tooth 50A-D further comprises a tapered leading edge 72, As shown, the tapered edge 72 is located on a first side of fourth tooth 50D and first tooth 50A and on a second, side of third tooth 50C, The tapered leading edge 72 is positioned to compliment the tooth profile of each tooth 50A-D. As shown, the tapered leading edge 72 is located on the side of each tooth 50A-D that is concave. This feature allows the tooth to scoop spoils out of the trench. Each tooth 50 comprises a connection point 74 on a first side 76 and a second side 78 for connection between the tooth 50 and the pivotal connection 62. As shown, the rollers 64 preferably comprise a roller diameter “R” larger than a height “H” of the support bars 62 of the links. In this way, rollers 64 provide rolling engagement between the trenching boom 14 (FIG. 1) and the digging chain 12.

With reference now to FIG. 4, the digging chain 12 is shown from above. The pivotal connections 62 provide for a gap 50 between adjacent pivotal connections and between the support bars 60 of each link 52A-B for engaging teeth of the trencher 10 sprocket. As shown, the hardened tip 70 of each tooth 50C-D protrudes from the tooth, though the hardened, tip may be integrally formed as well. The teeth 50C-D are shown replacing support bars of an external link 52A in FIG. 4, though the teeth may be placed on internal links so long as the shape does not interfere with pivoting of the links 52 and teeth 50 about the pivotal connection 62.

With reference now to FIG. 5, the digging chain 12 is shown having additional alternate teeth 150. The alternate tooth 150 is a right, left, or center-cut tooth such as the SHARK® tooth, though other teeth of this and other types may be utilized. As shown, alternate teeth 150 provide an alternate cutting profile and shape relative to teeth 50, and the combination of the teeth and alternate teeth may be advantageous. As shown, only one link 52 is between the teeth 50 and alternate teeth 150.

A first alternate tooth 150A is located in the first flight 68 and is oriented away from the digging chain 12. A second alternate tooth 150B is located in the second flight 69 (FIG. 2) and is oriented neutrally relative to the digging chain 12. A third alternate tooth 150C is located in the first flight 68 and has a different orientation than first alternate tooth 150A to give the third alternate tooth a separate digging profile. One of ordinary skill may appreciate that a fourth alternate tooth (not shown) and so on may be utilized in different configurations based, upon the particular needs of the digging chain 12, and that the particular orientations shown in this application are illustrative and not limiting on the particular orientations possible for use with digging chain 12.

Various modifications can be made in the design and operation of the present, invention without departing from its spirit. Thus, while the principle preferred construction and modes of operation of the invention have been explained in what is now considered to represent its best embodiments, it should be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described. 

What is claimed is:
 1. An endless digging chain formed from a plurality of pivotally interconnected links arranged in laterally spaced first and second flights, in which the plurality of links include: a first tooth positioned in the first flight and formed as a single-piece tooth having a first shape; a second tooth positioned in the first flight and formed as a single-piece tooth having a second shape different than the first shape; and a third tooth positioned in the second flight and formed as a single piece tooth.
 2. The endless digging chain of claim 1 wherein the first shape and the second shape are mirror images of one another.
 3. The endless digging chain of claim 2 wherein the third tooth comprises a third shape that is the same as the second shape.
 4. The endless digging chain of claim 1 comprising a plurality of untoothed links, wherein three of the plurality of untoothed links are located between the first tooth and the second tooth.
 5. The endless digging chain of claim 4 further comprising three of the plurality of untoothed links located between the second tooth and the third tooth.
 6. The endless digging chain of claim 1 further comprising a fourth tooth positioned in the second flight and having a different shape than the third tooth.
 7. The endless digging chain of claim 6 wherein the fourth link and the first tooth comprise the same shape.
 8. The endless digging chain of claim 7 wherein the endless digging chain comprises a repeating pattern comprising the first tooth, second tooth, third tooth and fourth tooth in that order.
 9. An endless digging chain comprising: a plurality of untoothed links defining a width: and a plurality of teeth, wherein the plurality of teeth are each pivotally connected on each end to one of the plurality of untoothed links, and wherein the plurality of teeth define a repeating pattern of four distinct tooth profiles relative to the width.
 10. The endless digging chain of claim 9 wherein a first distinct profile and a second distinct profile of the cutting teeth are mirror images.
 11. The endless digging chain of claim 9 wherein a first distinct profile and a third distinct profile are laterally offset relative to the width.
 12. A trencher comprising: a trencher boom; and the endless digging chain of claim 9, wherein the digging chain rotates about the trencher boom to uncover a trench.
 13. The endless digging chain of FIG. 9 further comprising a plurality of rollers disposed along the width of the plurality of untoothed links, wherein the rollers are rotatable independent from the untoothed links and wherein the rollers comprise a diameter which is greater than a height of the untoothed links.
 14. An endless digging chain comprising: a first flight comprising: a plurality of untoothed links; a plurality of single-piece first toothed links comprising a first shape and pivotally connected at each of its ends to one of the plurality of untoothed links; and a plurality of single-piece second toothed links comprising a second shape and pivotally connected at each of its ends to one of the plurality of untoothed links; wherein the first shape is different from the second shape; and a second flight comprising: a plurality of untoothed links; and a plurality of single-piece third toothed links comprising a third shape and pivotally connected at each of its ends to one of the plurality of untoothed links; and a plurality of connectors interconnecting the first flight and the second flight.
 15. The endless digging chain of claim 14, wherein the second flight further comprises a plurality of single-piece fourth links comprising a fourth shape and pivotally connected at each of its ends to one of the plurality of untoothed links.
 16. The endless digging chain of claim 15 wherein the fourth shape is the same as the first shape and the second shape is the same as the third shape.
 17. The endless digging chain of claim 14 wherein the first shape and the second shape are mirror images.
 18. The endless digging chain of claim 15 further comprising a repeating pattern of the first toothed link, second toothed link, third toothed link, and fourth toothed link, in that order.
 19. A trencher comprising: a pivotable trencher boom; an auger located proximate the trencher boom; and the endless digging chain of claim 13 rotatable about the pivotable trencher boom to uncover a trench; wherein the auger is positioned to remove spoils from proximate the trench.
 20. The trencher of claim 19 wherein the endless digging chain further comprises a plurality of rollers disposed between the first flight and the second flight, wherein the plurality of rollers are rotatably independent from the first flight and second flight and provide mobility for the digging chain about the trencher boom. 